1. Field of the Invention
The invention relates to a fuel cell manufacturing method and a fuel cell manufacturing system directly used in the implementation of the manufacturing method.
2. Description of the Related Art
A single fuel cell (single cell) is formed by sandwiching a membrane-electrode assembly (MEA) between separators. A module is formed by joining at least two single fuel cells together in a stack, and a stacked fuel cell is formed by stacking by a plurality of modules together (the direction in which they are stacked is arbitrary).
Japanese Patent Application Publication No. JP-A-2001-236971 discloses a continuous production method for a module. Although it is described as “continuous”, it is no more than an example of a well-known production method, and is therefore essentially a batch process. It is not a method for producing a separator and module by conveying a continuous strip of sheet material as it is, such as is the method according to this invention.
However, the related production method for a fuel cell module has the following problems.
1) In order to reduce space and effectively use the area of the electrode, which is costly, the two separators and the MEA must generally be precisely positioned when being assembled. Also, the separator distorts significantly by itself due to the fact that it is an extremely thin sheet. Therefore, in a conventional batch automated assembly, it takes a relatively long time to perform “distortion correction” and “positioning” without damaging the product, which creates a bottleneck that slows assembly down.
2) When assembly is done while the line is stopped using a fixed jig for precision positioning or distortion correction in 1) above, conveying time increases, thus creating a bottleneck that slows assembly down. Non-stop assembly is also conceivable, such as a method in which the jig and entire assembly apparatus are mobile and assembly is done while the separator is being conveyed, after which the jig and entire assembly system then return at high speed, or a method by which a plurality of apparatuses are circulated. These methods, however, have problems related to cost and space.
3) Since the separator and the MEA are shaped in thin sheets and there is no guide, and especially since a guide can not be used because the MEA is a part which has little flexural rigidity, then during assembly, it is necessary to hold the parts with an apparatus until there is sufficient contact between them. Since the assembly tool is positioned on a jig (the product) for a relatively long time during assembly, assembly is such that the conveyer line tends to stop, just as in 2) above, so that the relatively long conveying time becomes a bottleneck that slows assembly down.
The problem that this invention attempts to solve is the fact that it takes a long time to position separators with respect to other separators and separators with respect to MEAs according to the conventional fuel cell module manufacturing method.